1. Field of the Invention
The present invention relates to an iron type golf club head capable of improving a repulsion performance.
2. Description of the Related Art
In a golf game, it is advantageous that a ball travels far. For example, in an iron type golf club, it is possible to have a clear shot to the green by a club of a high number having a large loft angle. The club of the high number has a high trajectory, the ball tends to stop on the green, and a lateral deflection is a little. Accordingly, a score is improved.
In conventional, in order to increase a carry of the iron type golf club, a repulsion performance of the head is improved. In particular, there has been known methods of making a thickness of a face entirely thin, and of forming grooves or the like in a peripheral portion of the face. These methods deflect largely the face at a time of hitting the ball. However, in the head mentioned above, there is a case that a durability is deteriorated by making the face thin, and an effect of improving the repulsion performance is not enough.
Further, as shown in FIG. 7A and FIG. 7B showing a cross section taken along line A—A in FIG. 7A, there has been known a head “a” structured by a face plate “b” and a head main body “c” arranging the face plate “b” on a front surface thereof. The head main body “c” has an opening “d” extending back and forth. The face plate “b” comprises a non-supported part “e” in which a back surface is faced to the opening “d”. Since the non-supported part “e” is not clamped to the head main body “c”, it is useful for largely deflecting the face plate “b” at a time of hitting the ball.
In this case, a general ball hitting position P (shown in FIG. 7A) of the iron type golf club is normally concentrated on an approximately intermediate position between an end portion Et on a toe side of a face groove f formed on the face surface and an end portion Eh on a heel side, or on a slightly heel side position. Accordingly, in order to improve a head repulsion performance, it is desirable that a portion near the ball hitting position P is deflected at maximum.
However, as shown in FIG. 7C showing a rear view of a conventional iron type golf club head, a height “h” of the non-supported part “e” gradually becomes larger from the heel side toward the toe side. The non-supported part “e” can not make the deflection near the ball hitting position P larger. Therefore, in order to improve the repulsion performance of the head, there is further room for improvement.